itas dryflame engineering manual (metric) · 2020. 6. 12. · gas supply towards the burner and air...

EMDFM-20200515

ITAS DRYFLAME

ENGINEERING MANUAL (METRIC)

Version May 2020

The information provided on this brochure is for information purposes only and does not constitute any legal obligation or a warranty, expressed or implied, concerning quality, marketability or suitability for a specific purpose.

Copyright © 2020 - Fives - All rights reserved. May 2020

Copyright Copyright 2020 by Fives ITAS S.p.A. All rights reserved. This publication is protected and shall not be copied, distributed, transmitted, transcribed or translated in any form or by any means, to any third parties, without the express written consent of Fives ITAS S.p.A. Disclaimer / Responsibility declining The manufacturer will decline all responsibilities for damages to the product, machine or production or injuries to persons in any of the following cases:

- Improper use of the product; - Use of the product by non-qualified personnel; - Not following regulations of the country where the product is installed; - Improper erection of the product; - Improper integration of the product into any machine; - Use of parts other than manufacturers parts or advised by manufacturer; - Maintenance by unskilled personnel; - Exceptional events: - Not following instructions mentioned in this document.

Liability and warranty ITAS Dryflame burner is a “partly completed machinery” and cannot be used without further integration into a combustion system or machine. Fives ITAS S.p.A. liability limits to the product only. Fives ITAS S.p.A. will not be liable for any injury, loss, damage or expense (whether direct or consequential), including but not limited to loss of use, income, or damage to material arising in connection with sale, installation, use of, inability to use or repair or replacement of Fives ITAS S.p.A. products. It is the intention of Fives ITAS S.p.A. of making this manual as accurate and complete as possible. In case any typos, mistakes, errors or missing elements were found in this document, please bring them to our attention so we can correct them. This document is under continuous supervision and modification of Fives ITAS S.p.A. document specialists. Therefore, it is the users’ responsibility to make sure they have the most recent version of documents at any time.

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TABLE OF CONTENTS

1. INTRODUCTION ........................................................................................................... 4

1.1 Audience ............................................................................................................................. 4

1.2 Symbols .............................................................................................................................. 4

1.3 Assistance .......................................................................................................................... 4

1.4 Related documents ............................................................................................................ 4

1.5 Purpose of this manual ...................................................................................................... 4

2. THE PRODUCT ............................................................................................................ 5

2.1 Description ......................................................................................................................... 5

2.2 Intended use ....................................................................................................................... 5

2.3 Certification ........................................................................................................................ 5

2.4 Mechanical construction ................................................................................................... 5

2.5 Functioning ......................................................................................................................... 6

2.6 Control methodology ......................................................................................................... 6

3. BURNER SELECTION AND SYSTEM DESIGN .......................................................... 7

3.1 Burner selection ................................................................................................................. 7

3.2 Combustion air system ...................................................................................................... 8

3.3 Calculation example ......................................................................................................... 10

3.4 Gas supply system ........................................................................................................... 10

3.5 Burner Management ......................................................................................................... 11

3.6 Typical ITAS Dryflame (DF0250 and DF0500) system ................................................... 11

3.7 Burner connection to heater/ combustion chamber ...................................................... 12

4. NOTES ........................................................................................................................ 13



1. INTRODUCTION

All involved personnel shall carefully read the entire manual before integrating the product into a combustion system. If any part of the information in this manual is not clear, contact Fives ITAS S.p.A. before proceeding. This manual provides information regarding the design of the burners for their specific design purpose. Do not deviate from any instructions or application limits described herein without written approval from Fives ITAS S.p.A.

1.1 Audience

This manual is intended for engineers having experience with all aspects of combustion. These aspects include, but are not limited to, nozzle-mix burners and its related components such as gas trains, blowers and fans, burner management and air flow design.

1.2 Symbols

The warning signal used in this document indicates a subject requiring special attention when designing the combustion system. Improper design of the combustion system might result in death or injury when

operating the system.

1.3 Assistance

Should the user need any assistance, contact the local Fives ITAS S.p.A. representative or contact the Headquarter:

Fives ITAS S.p.A. Via Metauro, 5 – 20900 Monza (MB) – Italy Tel. +39 039 27331

1.4 Related documents

This engineering manual is provided together with, and cannot be used without: - Technical datasheets of the ITAS Dryflame burner series. Each burner size has its own

datasheet - Engineering manual of the ITAS Dryflame burner series (present document)

1.5 Purpose of this manual

The purpose of this document is to ensure a safe, effective and trouble-free selection of ITAS Dryflame burner and to support a trouble-free design of the combustion system where burner is to be integrated.

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2. THE PRODUCT

2.1 Description

ITAS Dryflame burner is a nozzle-mix burner designed for integration into a combustion system or machine. The burner is designed for:

- High turndown - Increased process efficiency - Simple adjustment

2.2 Intended use

ITAS Dryflame burner is designed for use on a wide range of industrial air-heating applications, direct- or indirect-fired. Typical industrial applications are:

- Industrial dryers - Paint booths - Curing ovens - Stenter dryers - Aluminium aging and homogenizing - Glass lehrs - Tempering lines

2.3 Certification

ITAS Dryflame burner complies with the EN746-2 and the machine directive 2006/42/EC. This can be confirmed by manufacturer’s Declaration of incorporation. ITAS Dryflame meets the technical specifications of the Eurasian Customs Union (EAC).

2.4 Mechanical construction

The burner is available in four (4) different capacity sizes from 250 kW lhv up to 1500 kW lhv. The on-ratio controlled gas- and air-valves are integrated into the burner body. The burner body is made of casted aluminium (2 smallest sizes) or constructed steel (2 largest sizes). A machined AISI310 nozzle and AISI310 combustor in 2 different lengths complete the design.

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Combustor

Body

Integrated gas- and air valves

Servo connection

Figure 2.1 – Dryflame part recognition



2.5 Functioning

After starting the combustion air fan, the operator shall push the “start” button. The burner control unit begins start-up cycle, including safety checks, and opens the gas safety shut-off valves to allow gas supply towards the burner and air supply towards the burner. Gas and air flow through their separated ways towards the burner’s nozzle. The combustible gas/air mixture is produced at the nozzle, downstream of the burner head. On ITAS DF0250 and DF0500, the gas/air mixture is electrically ignited by a spark electrode. A flame is produced, which will be monitored by a flame rod or UV-sensor. On ITAS DF0900 and DF1500, the gas/air mixture is ignited by the integrated pilot burner.

2.6 Control methodology

ITAS Dryflame burner offers integrated gas and air valves. The lambda of air versus gas is adjusted (fixed) by manufacturer before the shipment of the product. During operation, the air and gas ratio are constant over the entire turndown of the burner. A single control motor shall be assembled onto the burner to control the gas with air during burner operation.

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3. BURNER SELECTION AND SYSTEM DESIGN

3.1 Burner selection

The burner shall properly fit the application where it is meant to be used on. Use the ITAS Dryflame datasheets when following the selection process. Capacity input: A heat balance of the process defines the required heat input from the burner into the application. Consider all aspects like system efficiencies, preheat temperatures and number of burners to determine the required capacity input from the burner. As far as the capacity data are concerned, it shall be noted that the capacities in kW and energies in kWh/m³ relate to net heating values (=lhv).

Never exceed the maximum and minimum capacities as per product’s technical datasheet. This might cause flame instability and unsafe circumstances.

Turndown required: The minimum capacity input is indicated in the burner’s technical datasheet. Flame dimensions: Make sure the burner’s flame dimensions fit the application. Diameter and length of the flame are provided in the technical datasheet. At the minimum operating conditions (minimum capacity input) the entire flame remains inside the combustor tube. Combustor material: Standard ITAS Dryflame burner is delivered with a stainless-steel combustor. Make sure the process temperature does not exceed the burner’s maximum allowable temperature as indicated in the technical datasheet. Combustor length: The combustor length shall be selected to ensure that the burner might be installed onto the machine in a proper way. ITAS Dryflame burner has 2 standard options for combustor length and nozzle position. The outlet of the combustor shall not stick into the lining or refractory of the heater wall. The heater wall shall be adapted to the position of the nozzle. See chapter 3.7 to learn more about heater wall design. Fuel type: Make sure the fuel is suitable for use on ITAS Dryflame burner. Natural gas net heating values shall be 8 kWh/Nm³ or higher. The Fuel pressures indicated in the technical datasheet are based on the gasses specified in that datasheet. A correction of the gas pressure at the burner when running fuel gas with deviating caloric value and/or density may be necessary. The required pressure may be calculated with:

p2 � p1 ∗ ��

�∗

��

�

p1 = adjustment pressure for reference input [mbar] (from technical datasheet)* p2 = adjustment pressure for actual input [mbar] ρ1 = density of reference fuel [kg/Nm³] (from technical datasheet) ρ2 = density of actual fuel [kg/Nm³] hv1 = heating value of the reference gas [kWh/m³] (from technical datasheet) hv2 = heating value of the actual gas [kWh/m³]

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Flame supervision: As a standard, ITAS Dryflame burners are supplied with Flame Rod for flame supervision. As an option, control with a UV-sensor is possible. This replaces the Flame rod and is fit to the same connection on the burner. Make sure that the type of flame supervision is compatible with the burner control unit used in the control panel. Also make sure that the signal is strong enough and wired separately from other components in order not to be disturbed. For detailed information on flame-scanner installation and connection, refer to the supplier’s literature.

Capacity control: Standard the burners DF0250 and DF0500 are provided with a bracket for installing a control motor model SQN31. It is important to select a motor with enough torque [Nm] and opening counter clockwise.

Ignition system: For proper ignition of the burner, Fives ITAS S.p.A. recommends using a transformer with secondary voltage of 6 to 8 kVAC and a minimum secondary current of 20 mAmps at full wave output. DF0250 and DF0500 are direct ignited by the spark rod. The DF0900 and DF1500 are ignited via the integrated pilot.

Firing position: ITAS Dryflame burner can fire vertical down or horizontal. Vertical down requires a continuous running combustion air fan. Please notice that the functioning of the add on components might be affected by its position. Combustion air supply: Designed for the available supply voltage, system back pressure and elevation above sea level, ITAS Dryflame burner can be equipped with a combustion air blower. It is possible to have an external source supplying combustion air to the burner too. Make sure the correct amount and flow are delivered (values may be found in the Technical datasheet) and piping is prepared in order to have uniform flows into the burner. See chapter 3.2 for more information. Combustion air inlet: The burner body can be positioned with the combustion air coming from top, from the left, from the right or coming from the bottom. The gas inlet is positioned on the opposite side of the burner body.

3.2 Combustion air system

The values in the Dryflame technical datasheet are all based on environmental “Nominal Conditions”, defined as:

- 20°C (293,15 K) - 1 atm (1013,25 mbar, 101,325 kN/m², 101,325 kPa)

Deviations on the above might come from pre-heating combustion air, elevation above sea level or different pressure conditions. The maximum burner capacity may be reduced when operating on non-nominal conditions. Consider the proper volume of combustion air to have a complete combustion of fuel at maximum input.

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Burner Model Control motor

Minimum torque [Nm]

DF0250 3

DF0500 3

DF0900 On request

DF1500 On request



The volume of the combustion air supply shall match the burner and application requirements. Combustion air shall be fresh (20,9 % O2) and free of contaminants. Fives ITAS strongly recommends the use of a combustion air filter to remove airborne particles. No corrosive fumes or particles shall be supplied to the burner. The combustion air can be supplied by a blower directly assembled onto the burner or by an external source, connected via piping. It is important to have a uniform flow distribution for combustion air coming into the burner.

Do not modify the factory setting of lambda between gas and air. This might cause uncomplete combustion, emission formation or other unsafety circumstances.

Make sure the external combustion air supply delivers the correct amount and pressure of air to the burner connection flange. (Values may be found in the burner’s technical datasheets)

The pressures indicated in the technical datasheet are based on the air temperature specified in such datasheet. A correction of the pressure at the burner when operating other temperature combustion air may be necessary. The required pressure may be calculated as follows:

p2 � p1 ∗ ��

�

p1 = adjustment pressure for reference temperature [mbar] (from technical datasheet)* p2 = adjustment pressure for actual temperature [mbar] T1 = reference temperature [K] (from technical datasheet) T2 = actual temperature [K]

If the burner shuts off during operation at application temperatures above 50°C, provisions must be made to provide an adequate cooling of the burner internals.

Install a pipe union or flange in the air-line to the burner. This simplifies installation and removal of the burner during commissioning or maintenance. The use of flexible pipes (expansion joints) is recommended to absorb stress due to heat expansion and slight misalignment. Be aware that flexible pipe nipples might cause inaccurate measurements of pressures during commissioning.

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3.3 Calculation example

An application requires 690 kW of net heat input, delivered by 3 burners. The system operates on Russian Natural gas (lhv = 9,97 kWh/m³, stoichiometric air/gas ratio 9,56 m³/m³). Burner will operate at 20% access of air (=Lambda 1,2) Combustion air is taken from ambient at 20°C (<200mAsl)

a. Select the most appropriate Dryflame burner model: Qt = total heat input [kW] n = number of burners [-] Q = heat input burner [kW]

��

��

��

�� 230��

Select ITAS Dryflame model DF0250 based on the required 230kW

b. Calculate the required gas flow: Vgas = Gas flow [m³/h] lhv = net heating value of the gas [kWh/m³]

� !" �

#$%�230

9,97� 23,07)�/$

c. Calculate combustion air flow requirement

Vair = Air flow [m³/h] ɑ = stoichiometric air/gas ratio [m³/m³] λ = Lambda [-]

�!+� � ! , � !" , λ � 9,56 , 23,07 , 1,2 � 265m�/h

3.4 Gas supply system

The gas valvetrain shall be designed in a proper and safe way to supply the correct amount of fuel gas at the right pressure to the burner. The required gas pressure at the inlet of the burner’s gas gun can be read in graph 3 in the technical datasheet (Figure 3.1). The gas train shall comply with all local safety standards and codes. Regulations shall be, but not limited to:

- EN 746-2 and machine directive - NFPA with listing marks from UL, FM, CSA

Make sure high-quality safety components are used and assemble these as per suppliers advise. Pipe diameters shall be selected correctly. High gas-flow velocities may create noise and high pressure-drops shall be avoided. Fives ITAS S.p.A. may support in the design and delivery of the main gas train for fuel supply to the burner.

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Figure 3.1 – Gas differential pressure example



Be sure the burner operates at proper gas- and air ratios. Too low air flow might causes uncomplete combustion, emission formation or other unsafety circumstances.

3.5 Burner Management

The combustion system shall be equipped with a management system. The management system shall apply to local regulations and shall be equipped with, but not limited to, burner relay, temperature safeguarding and pressure alarms. Contact Fives ITAS S.p.A. in case of any doubts or questions.

3.6 Typical ITAS Dryflame (DF0250 and DF0500) system

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Pos. Instrumentation

01 Ball valve/ manual shut-off valve

02 Flexible/ compensator

03 Dirt trap/ filter

04 Manometer with push button

05 Double safety shut-off

06 Max. gas pressure switch

07 Min. gas pressure switch

08 Gas pressure regulator

Pos. Instrumentation

09 3-way solenoid valve

10 Blower motor

11 Combustion air blower

12 Combustor tube

13 ITAS Dryflame burner head

14 Spark plug

15 Flame rod/ UV-scanner

16 Combustion air pressure switch

17 Servomotor for gas/air control

Figure 3.2 – Typical PID ITAS Dryflame burner system



3.7 Burner connection to heater/ combustion chamber

Use the burner’s assembling flange to connect the burner to the application. - Make sure the heater wall is strong enough to bear the weight of the burner.

(see technical datasheet for burner weight) - Create 12 mm space between combustor outer diameter and opening in the heater wall to

allow for thermal expansion and easy assembling and replacement of the burner onto the heater wall. (see figure 3.3)

- Install a gasket between the burner flange and the heater wall. Make sure the gasket does not leak.

- The velocities of process air perpendicular on the burner flame shall be between 4 and 15 m/s (the optimum is 10 m/s), (see figure 3.3) Lower air flow velocities may result in cooling issues on the burner’s combustor tube. Higher velocities may result in flame instability and formation of high emission levels. For higher air flow velocities, it is necessary to protect the flame with an additional flame shield. (see figure 3.4)

- The outlet of the combustor shall not stick into the lining or refractory of the heater wall. (see figure 3.5)

- The heater wall shall be adapted to the position of the nozzle.

Figure 3.3 - Burner installation and flow

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Burner

Minimum Diameter "A"

Length “B” [mm] 30% flame coverage (min)

DF0250 350 250

DF0500 400 300

DF0900 … …

DF1500 … …

Air flow

Figure 3.4 – Flame shield design

Figure 3.5 – heater wall adapted to nozzle position



4. NOTES

On this page personal engineering notes may be taken.

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itas dryflame engineering manual (metric) · 2020. 6. 12. · gas supply towards the burner and air...

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